1. Technical Field
The present invention relates to an image forming material.
2. Related Art
In recent years, techniques of drawing up documents or the like through the recording of invisible information lacking viewability under normal visual conditions have been received attention. These techniques are useful e.g. in management of security and embedding of Internet information and sound, and allow improvements in added value of the documents or the like.
As an example of a method for recording invisible information, there is the method of using an image forming material which has absorption in the near-infrared region of 750 to 1,000 nm and can be detected by a silicon-utilized light-sensitive element (CCD or the like) although it cannot be recognized by human eye.